Verfahren zur Anpassung eines adaptiven Hybrids an eine Leitung

Methods for matching adaptive hybrids (15) to lines (16) for making reflectograms of the lines (16) measure (1) input impedances (Zmeas) of the lines (16), model (2) characteristic impedances of the lines (16) via physical models (Zphymod), estimate (3) parameters of the physical models (Zphymod) via cost functions which depend on the measured input impedances (Zmeas), convert (30) the modelled characteristic impedances into impedance values (13), and set (31) the adaptive hybrids (15) with the impedance values (13). Unwanted near-end reflections are minimised and wanted reflections can be measured. The physical models depend on frequencies s, Bessel functions Ji and parameters ai related to geometrical dimensions A, D and L and material constants sigma , epsilon and mu of the lines (16). The method may further model (6) characteristic impedances of the lines (16) via rational function models (Zrafumod) and estimate (7) parameters of the rational function models (Zrafumod) via further cost functions which depend on outcomes of the physical models (Zphymod).